The substitution of minerals for tropical crops in exports were the game-changer in the economic specialisation patterns of post-colonial Africa. However, compared to economic historical research on the 19th century commercial transition, the long-term evolution and consequences of Africa’s ‘mineral transition’ remain poorly understood. Using new annual data on all the major export commodities for each African country 1890-2022 we study Africa’s mineral transition in a long-term perspective. Exploiting the fact that about half of African countries south of the Sahara have experienced this transition, while the other half retained its original crop-based export package, we analyse three critical dimensions of this transition: (i) long-term prices and terms-of-trade; (ii) economic growth, macro-economic stability and poverty reduction; (iii) crowding out: did mineral export revenues lead to commercial agricultural neglect (e.g. due to declining fiscal dependence), or were mineral revenues instead used to revitalize the agricultural sector? Our evidence supports a mixed narrative that emphasises both missed opportunities of rural development and pro-poor growth, but also points to the gloomy counterfactual of development in non-mineral economies.